Today, there are solutions for performing a teleconference with several participants, such as terminal users and machines, which are linked by a telecommunications network. A common usage of teleconference is to conduct a meeting or the like with participants that are located remote from each other. A conference call can be configured such that a calling party calls the other participants and adds them to the call. Further, participants are also able to call into the conference call themselves by dialing a telephone number that connects to a conference bridge which is a specialized type of equipment in the network that links telephone connections used by the participants. A specialized service provider maintains the conference bridge and provides phone numbers and PIN codes that participants can use to access the conference call.
A central control node, commonly referred to as a “floor control server”, is often employed for enabling and controlling a teleconference by granting permission to speak or enter other input. In this context, the term “floor” refers to a technology or platform used for making input to the conference. Common examples of a floor include speech, video, messaging, file sharing and whiteboard. Several different floors may be used at the same time in a teleconference and the floors may be maintained and controlled by specific centralized nodes commonly called “floor chairs” being associated with the floor control server. Alternatively, the floor chair function may be implemented in the floor control server.
FIG. 1 illustrates a conventional teleconference handled by a central floor control server 100 and where multiple floor participants 102, i.e. communication terminals, can communicate with each other using shared “conference resources” 104 supporting one or more floors, which could be a bridge for voice or video streams, a whiteboard, etc., depending on what floors are used. Each floor is managed by a floor chair 106 associated with the floor control server 100. In this example, a floor participant 102a obtains permission to speak from the floor control server 100, shown by two-way arrows, and is then able to speak over the resource 104 such that his speech is conveyed to all the other participants 102, as indicated by dashed arrows. If another participant is already speaking, the requesting participant 102a can be placed in a queue to wait for his turn to speak. The floor chair 106 maintains a floor record with information about utilization of its corresponding floor.
The 3rd Generation Partnership Project, 3GPP has defined a technical solution for conferencing within an IP Multimedia Subsystem, IMS, based on the Session Initiation Protocol, SIP and the Binary Floor Control Protocol, BFCP. In traditional centralized conferencing systems, floor control is implemented using the BFCP for communication of control messages between the floor control server and the participants.
BFCP can thus be used to send floor control requests from conference participants to floor control servers e.g. requesting permission to speak, and to coordinate access to shared conference resources by granting or denying the requests. BFCP can be used between participants and floor control servers, and between floor chairs and floor control servers. In addition, floor chairs can use BFCP to send floor control servers decisions regarding floor requests. BFCP can also be used by floor control servers to inform floor chairs and floor participants about the status of the floors and the floor requests.
However, it is a problem that various centralized components with control functions are required, such as the above-described floor control server and floor chairs, which may limit the possibilities for establishing new teleconferences, e.g. in terms of capacity, conference resources, subscription restrictions, and so forth. Using centralized control functions for teleconferencing between multiple participants in a communication network is thus highly dependent on availability and performance of the central components, also demanding costs for configuring, operating and maintaining the central components. It is furthermore a somewhat vulnerable solution in that the teleconference may be impeded or otherwise negatively affected if any of the central components is out of order or malfunctions in some way.